Table 3.

Effect of Birth Center Use on Maternal and Infant Outcomes (All Women, Instrumental Variables Analysis)

	FHBC (%) (N = 872)	Usual Care (%) (N = 56,073)†	Difference (Percentage Points)	Marginal Effect
Bivariate probit regression
Cesarean section	19.7	29.6	−10.0	−10.5**
Use of vacuum or forceps	2.1	4.6	−2.5	−3.3**
Electronic fetal monitoring	78.2	83.3	−5.1	−10.2*
Weekend delivery	28.6	23.4	5.2	11.7*
Preterm birth (≤36 weeks)	7.9	11.0	−3.0	−6.2**
APGAR 5 score <7	3.4	3.6	−0.27	0.209**
Low birthweight (<2,500 g)	8.4	10.2	−1.8	−1.6
Vaginal birth after cesarean section‡	26.7	9.3	17.3	57.7**
2SLS
Average birthweight (g)	3,245	3,164	81	76
Average birthweight at term (g)§	3,325	3,278	46	45

*p < .05; **p < .01.

^†We did not use zipcode in the propensity score reweighting for this analysis as it is the basis for the instrument, and as a result the N is larger than in Table 2.

^‡This analysis was restricted to only women who had a previous C-section (N = 4,171 for the usual care group and N = 45 for the Family Health and Birth Center [FHBC] group).

^§N = 48,769 for average birthweight at term.